Protein isolate products have protein contents (determined as Kjeldahl nitrogen.times.6.25) of at least 90%. Those protein isolates which are separated commercially from plant protein materials, such as, soybean, are usually substantially denatured and have little or no functionality.
Some naturally-occurring proteins, such as, egg white and wheat gluten, exhibit functionality, that is, they become involved in the overall molecular architecture of the product in which they are present, as well as nutritional benefits. The proteins are more desirable than the nonfunctional isolates and as a result command much higher prices. As far as we are aware, substantially undenatured functional protein isolates from plant protein sources have not been formed.